On our return from Florida, we toured Luray Caverns, an impressive limestone cave with many colorful formations. The cave was eroded by acidic waters flowing through vast, ancient sea beds after the beds were folded and raised by the Americas collision with the Eurasian continent in the making of Pangaea and the Appalachians, hundreds of millions of years ago. Over hundreds of thousands of years, water seeping down from overlying soils dripped carbonates often tinged with irons and copper, creating fantastic columns and masses of colorful crystalline rock. The first photo shows the 25-foot-tall Leaning Column, thought to resemble the Leaning Tower of Pisa. The second photo shows an accumulating Fried Egg formation.
The one-hour tour goes about a mile as it winds down among the famous formations to the water table, which still hides more cave below.
The active formations grow very slowly. As the ground water flows over the forms, it gives up some carbon dioxide and precipitates the calcium carbonate, which slowly accumulate into an assortment of ornate drip and flow stones.
Cave formations today have uses beyond tourism; they also are a focus of climate research, having preserved over long periods of time many aspects and phases of the earth's highly variable climate.
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